Electric hammer.



A. wENDELBuRG.

ELECTRIC HAMMER.

l APPLICATION FILED JULY 28. |914.

Patented Dee. 18, 1917 Arm/Mfrs UNITED sTATEs PATENT voE-Ercll Lux wmmuna, or NEW'YonxvN. Y., Assmann To rn'rsntmen ma Toor. comm, or NEW Yoan, N. Y., A conron'non or Pmsnvmlu.

nLEcTnrc Specincation Letten Patent. Patented bec. 18, 1917.

4Application med July 28, 1914. Serial No. 858,784.

To all 'whom t may concern.'

Be it known that I, ALEX VVENDELBURG, a citizen of the United States, residing in the city of New York, county of New York, and State of New York, have invented certain new and useful Improvements in Electric Hammers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to electric hammers adapted for usein chipping, calking, `riveting, cutting and otherl work requiring a rapid succession lof blows upon a suitable tool. The invention is directed to the provision of an improved form of electric hammer which is simple in construction, which may be manufactured at low cost, which is so constructed as to permit of cooling it by immersing it in a liquid, which is of comparatively light weight vand which possesses such strength and rigidity as will enable it to withstand the continual jarring to which it is subjected in use.

@ne of the features of the invention resides in so constructing the hammer as will permit or" immersing its main body portion in a liquid without danger of injury to the coils or other portions of the structure. By reason of this, provision for a water circulation through or around the structure of the hammer or anyy other means for preventing overheating is unnecessary. Instead, the operator may have a bucket of water near him and, at intervals, when the use of the hammer is temporarily discontinued, he may place the main body portion of the hammer in the water to the desired extent so as to cool it.

The, invention also involves the provision of an improved form of circuit-controlling ,mechanism whereby the' operation of the hammer is governed. This involves the provision of a cavity in the handle of the hammer in which a circuit-breaker of special form is removably mounted, this clrcuit breaker being operable to open and close the circuit to the coils of the hammer. The construction of the circuit-.breaker isl su'cli`"-as to mg at the terminals by the rovislon of auxilia .contaet surfaces whic effect a delayed brea ngof the circuit.

The invention also involves numerous other features of improvement in the construction of the hammer whereby great strength,good wearing qualities and ample protection of the parts are obtained. 'These and other features of the invention will be better understood by reference to the following description taken in connection with the accompanyin drawing which shows the preferred em odiment of the invention.

In the drawing, Figure 1 is a central sectional view of a hammer embodying my invention;

Fig. 2 is an enlarged sectional view through the circuit-controlling mechanism;

Fig. 3 is a transverse section of the circuitcontroller on line 3-jof Fig. 2; and

Fig. 4 is a diagram of the circuit connections. y

Referring to these drawin the frame of the hammer consists primarily of a tubular casting 4 and a'handle casting 5. The casting 4 is of non-magnetic material, preferably phosphor bronze, and the tubular passage therethrough contains a reciprocating solenoid core or plunger 6, adapted to strike Y the end of a tool to be inserted through the hollow tool-guide 14, hereinafter mentioned. The casting 4 is provided with radially dis` posed walls 7 8 and 9, which rovide spaces between them for solenoid lco1ls 10 and 11. These coils are wound in opposite directions and serve to develop magnetic fields which actuate the plunger 6 constituting the core of the solenoid. The coils are inclosed by a casing 12 which is preferably -a piece of steel tubing. This tubing and the walls 7, 8 and 9, are of such dimensions that the tubing fits snugly around the walls, and the spaces between the walls 7, 8 and 9, and the casing 12 are completely filled by the coils 10 and 11. The forward ends of the `casting 4 andthe casin 12 are connected together by a nozzle thread with whic the nozzle 13 coacts and the nozzle is formed with a projecting flange adapted to fit tightly over the end of the.

casing 12, as shown. The forward end of thevhammenis provided with a tool guide 14of slightly smallerinternal diameter, so that the plunger cannot slip out. This vtool guide is preferably vformed to fit into theend of the casting 4 and have threaded engagement with the end of the nozzle 13. By this construction, the forward ends of the casting 4 and the casing 12 are rigidly connected by the nozzle 13 so as to preclude relative movement of these parts, and the nozzle effects such a tight fit with the guide and casing as will preclude the entrance of a liquid between these parts when the forward end of the tool is immersed, in use, or for purposes of cooling.

At the opposite end of the hammer, the central passageway through the casting 4 is provided with an enlargement for a cushioning spring 16 to receive the blow of an impact block 15. A portion of this block 15 lies within the tubular passage through the casting 4 inwhich the striking plunger 6 reciprocates. The remainder of the block 15 is of larger diameter and lies within the enlargement of the tubular passage. The

coiled spring 16 bears at one end upon the circuit-controller with his thumb. The parts block 15, the latter being provided with a peripheral flange 17 encircling the end of the spring so as to hold the latter against lateral movement. Between the larger portion of the block 15 and the wall at the end of the enlarged chamber is a washer 18 of ing 'of the spring upon the walls of its inclosing chamber and consequent lack of uniformity in the action ofthe spring arel prevented.

The casting for the handle 5 has a central opening therethrough in which the rear ends of the casting 4 and the casing 12 are received. For securing these parts together,

the casing 12 may conveniently have a sleevek 20 secured-thereon by means of rivets and forming a circumferential flange. The tubular end 21 of thehandle casting 5 closely incloses the end of the casing 12 and is eX- teriorly threaded to coact with a ring or collar 22 on which is a lip 23 adapted to engage the flange 20. When the sleeve 22 is screwedl upyti htl the end 21 of the handle casting '65 and t e 11p 23, both of which closely inclose the casing 12, engage the flange 29, on opposite sides thereof and 'grip the handle casting 5 to the casing 12. The casting 5 is also interiorly threaded to coact with a threaded plug 24 which fits closely around the adjacent end of the casting 4, its end abutting against a flange 25 thereon. both the casing 12 and the casting 4 are connected to the handle casting 5 and these connections are such tight ones that they not only afford the necessary degree of strength, but also preclude the passage of water through them.

The plug 24 is provided with a hole through the center thereof as are also the caps 19 and 15. Because of this provision, air may pass freely from the space between the block 15 and the striking plunger 6 as may also any water which enters this space. The plunger 6 is preferablyprovided with a radial slot from end to end as is shown for guarding against the flow of eddy currents 1n the core or plunger 6.

Thev flow Vof' current in the coils of the solenoid is controlled by a switch or circuitbreaker located in a cylindrical cavity formed in the handle casting 5 directly above the grip 55 of the vhandle where the operator may readily press the button of the of this circuit-controller are located within a tube of insulating material and may all be assembledv within this tube before the latter is inserted in its cavity within the handle casting. Also, the parts of this circuit'- controller are specially constructed so as to provide for av hard rubbing engagement of the contacting surfaces and a delayed break of the circuit at auxiliary contacts. The construction of the circuit-controlling apparatus is shown more clearly in Fig. 2. In the bottom of the cavity in the handle casting 5 are a washer 26 and block 27 of insulating material both of which are remov- In this way,

ably held in place by a screw 50, as Shown in dotted lines in Fig. 2. In the insulating v block 27 are two contacts 28, which have wires connected thereto which pass through a passage 29 formed in the casting '5 and are connected to terminals upon a block 30 of insulating material which is secured upon the casting 4 in the space between the latter and the end of the easing 12. The contacts 28 are adapted to be engaged by the ends of pins 31 located in a cylindricall block 32 of insulating material which is secured in the end of a tube 33 of insulating material of a size adapted to fit snugly within the cavity formed in the casting 5. Thisvblock 32 is secured to the tube 33 by one or more pins 34. The opposite ends of the pins 31 are threaded into contacts 35 which are of therein which receives a sprin semi-circular form and are secured upon the block 32 directly opposite each other. The ends of these contacts 35 rising from the block 32 are-spaced apart and on their adjacent sides the)7 are provided with inclined urved depress1ons as shown at 26. (See A second block 37 of insulating material is secured in position within the tube 33 and forms a guide for a movable contact carrier 38. This carrier has the contact .39 secured thereon, this contact being in the form of a cup or bell the skirt of which is slotted so as to form a plurality of resilient contactfingers. The contact carrier 38 has a cavity formed 42 bearing upon a washer of heat-insulating material resting on the enlarged end 43 of a short rod 44 carrying an auxiliary contact 45. This auxiliary contact is of conical form as sho-wn. The rod 44 is adapted to slide in the opening provided for its reception in the contact carrier 38. The spring 42, being inclosed in a chamber whose walls are of heat -insulat ing material is correspondingly protected press button 46. When the parts of the circuit-controller have been assembled within the tube 33 of insulating material, the latter is moved into the cavity in the handle 5 and the end of that cavityis inclosed by a threaded cap 47.

The wires for carrying current to and from the hammer enter the structure through a passage 48 provided in the handle casting 5. A connection block 49 of insulating material carrying three terminals insulated from each other is preferably provided upon the casting 5, at this point, to which block the wires leading to the hammer are connected.

The wiring forcarrying current to and from the hammer is illustrated diagrammatically in Fig. 4. By reference to Fig. 4, it will be noted that two of the wires or conductors pass from terminals on the insulating block 49 to the block of insulating material 30, and, from said block 30 are con-l tinued by other wires until they are connected respectively to the non-adjacent ends of the coils 10 and 11. The adjacent endr-l of these coils are connected together, and, from their point of connection, a wire leads to the block 30, and iS continued by anotherI wire from the block 30 to one of the con-- tacts 28. From the other contact 28, a wire leads to the third terminal upon the insulating block 49. These connections are such that the connection from the junction of the l two coils 10 and 11 to the other side of the circuit may be opened or closed by the circuit-breaking mechanism located in the connected or dlsconnected by the bell 39 and y auxiliary contact 45. In Fig. 4, the insulating block 30 is shown as provided with individual grooves for the rece tion of the several wires or conductors re erred to. In assembling and dis-assembling the hammer, the wires leading from the insulating block 40 and from one of the contacts 28 to the insulating block 30 can be electrically connected with the continuations of those wires respectively, byvmeans of suitable connecting and disconnecting screws 56, as will be readily understood. i l

When the button 46v is pressed, the contact 39 and auxiliary contact 35 are moved forward and the latter engages the inclined surfaces 36 upon the contacts 35, so closing the circuit. As the movement of button 46 is continued, the auxiliary contact 45 is moved backrelative to the contact carrier 38 thereby compressing the spring 42. As this takes place, the contact 39 moves over the contacts 35 so as to effect an electrical connection between them. By reason of the resiliency of the slitted skirt of the bellshaped contact 39, a good rubbing engagement of the contact 39 upon the contacts is obtained. Furthermore, the conical form of the auxiliary contact 45 causes the contacts 35 to spread somewhat so that they are forced apart and therefore effect a more intimate engagement with the contact 39. When the pressure on the button 46 is relieved, the spring 41 forces the contact carrier 38 and the contact 39 upwardly so as to interrupt the connection of the contacts 35 by the contact 39. While this is taking place, however, the auxiliary contact 45 does not immediately disengage the contacts 35 for the reason that it is still kept in contact with them momentarily by the spring 42. After the contact 39 has moved away, however, a distance sufficient to clear contacts 35, the contact 45 disengages those contacts so as to break the circuit. As a consequence, whatever arcing there is takes place between the contact 45 and the surfaces 36., and has no effect upon the surfaces of contact between the slit bell 39 and the outer peripheries of the contacts 35, which therefore r'emain constantly bright and in elicient conductive condition. y

The circuit-breaker herein described may be readily constructed at low cost by assembling the parts within the insulating tube 33 and thereafter inserting that tube in the cavity in the handle of the hammer. In operation, this circuit-controller serves to close and open the circuit effectively, a good contact of large surface area being insured by the arrangement of the contact 39 to inclose the two contacts 35 and the contact 45 to spread the contacts 35 into hard engagement with the contact 39. The construction described above also permits the tube 33 and the switch apparatus mounted therein, including the contact pins 31, to be readily removed without disconnecting the wires from the contacts 28 with which the pins are adapted to engage when the tube 33 is in place.

It will be noted that the construction of the hammer is such as will permit of cooling it by inserting the whole of the forward portion of the hammer in a cooling liquid. The coils 10 and 11 are so inclosed and the con-- nections between the inclosing parts are such that the entrance of the cooling liquid into the chambers for the coils is precluded.

To further insure this result, the flange 57 is brazed to the shell or casing 12, and a thin asbestos gasket 58 is inserted at the point indicated; in addition to which the screw-threads connecting the nozzle 13 to the end of the casting 4 and to the tool guide 14 may be shellacked before assembling the parts, thereby making absolutely watertight joints.

While the parts of the hammer are connected together with such strength and ri- 'dity that the continual and severe jarring lncident to the use of the hammer will not cause the parts to work loose, they may be taken apart by unscrewing collar 22 which permits the handle to be drawn off of the end of casing 12 carrying with it plug 24. The various circuit wires within the handle should have sufficient slack to permit the handle to be drawn off of the end of casing 12 far enough to obtain access to the terminal block 30 from which they may then be disconnected, but since the terminal block is fastened to the frame member 4 the connections between the coils and the terminal block need not be disturbed after having once been made. The tool steel washer 18 which receives the return blow of the block 15 is fixed in position within its cavity, preferably by sweating it in place, in order that it may not follow the upward movement of said block.

What I claim is:

1. An electric hammer comprising the combination of a frame member formed with a tubular portion having walls extending radially outward therefrom and an enlarged chamber at one end of said portion, a striking solenoid core plunger reciprocating in sald tubular portion, a spring located in said chamber, an impact block coacting with the spring and plunger and having a portion fitting within the tubular portion of the frame member and an enlarged ortion fitting within said enlarged cham er, a casing inclosing the frame member and tting against said walls, and a solenold coil in the space between the casing and the tubular portion of said frame member; substantially as described.

2. An electric hammer comprising the combination of a frame member formed with a tubular portion having Walls extending radially outward therefrom and an enlarged chamber at one end of said portion, a striking solenoid core plunger reciprocating in said tubular portion; a spring located 1n said chamber, an. impact block coacting with the spring and plunger and having a' portion fitting wlthin the tubular portion of the frame member and an enlarged portion fitting within said enlarged chamber and provided with a flange surrounding the end of the spring, a casing inclosing the frame member and fitting against said walls, and a solenoid coil in the space between the casing and the tubular portion of said frame member; substantially as described.

3. An electric hammer comprising the combination of a frame member of tubular form having a passage therethrough, an enlar ed chamber at the end of the passage, a stri ing plunger reciprocating within the passage, a spring located in said chamber, an impact block coacting with the s ring and plunger and having a portion tting within the tubular portion of the frame member and an enlarged portion fitting within said enlarged chamber and provided with a ange surrounding the end of said spring, a washer through which said impact block extends lying at the bottom of said chamber and adapted to receive the return blow of the block when the latter is returned by the spring, a casing inclosing the frame member and a solenoid coil in the space between the casing and the frame member; substantially as described.

4. An electric hammer comprising the combination of a frame member of tubular form having an enlarged chamber formed in one end thereof, a striking plunger reciprocating within said member, aspring located in said chamber, a cap closing the end of the chamber and coacting with said spring, a casing inclosing said member, a solenoid coil in the space between the casing and said member, a handle secured to the casing and a plug secured to said handle and inclosing the end of said member having the chamber formed therein; and serving to lock said cap against rotation induced by vibration of the hammer; substantially as described.

5. An electric hammer comprising the combination of a frame member of tubular form, a striking plunger adapted to reciprocate in the passage through the frame member, aspring located'in said passage, a

cap closingl one end of said passage and c0- acting wit one end of the spring, aa impact member'located in said passage and coacting with the other end of the sprin and with the striking plunger, a plug inc osing the end of said frame member and said cap to lock said cap against rotation induced by vibration of the hafnmer, said cap, vsaid impact member and said plug having openings therethrough, a casing inclosin the frame member and a solenoid coil in t e space between the casing and said frame member; substantially as described.

6. An electric hammer comprising the combination of a frame member of tubular form having a passage therethrough and an enlar ed chamber at one end of the passage, a striing plunger reciprocating in said passage, a spring located in said chamber, Ia cap closing one end of said chamber and coactlng with one end of the spring therein, an impact member coactin with the other end of the s ring and with the striking1 plunger and aving a portion fitting wit inthe 'assa e of the .frame member, and an enlizrge portion fitting within the enlarged chamber and provided with a flange surrounding the end of the spring with which the impact member coacts, said impact member and said cap each having an opening therethrough, a casing inclosin the frame member and a coil in the space etween the casin and frame member; substantially as descrl ed.

An electric hammer comprising the combination of a frame member of tubular form, a plunger reciprocating therein, coils encircling the frame member, a casing inclosing said coils, an annular nozzle threaded upon one end of the'frame member and brazed to the adjacent end of the casing, a tool guidethreaded to the outer end of said nozzle and litting within the end of the -frame member, a gasket clamped between the end of the frame member and said nozzle for preventing the entrance of water past the threaded connection of said nozzle and said frame member, a s ring located within the frame member at tlie other end thereof, an impact member within the frame member between the spring and said plunger, and means for connecting the end of the frame member adjacent to said spring to the casing; substantially as described.

8. An electric hammer comprising the combination of a frame member conslsting of a tube enlarged at one end to form a chamber and radial walls formed on the tube, coils wound on the tube between said walls, a tubular casing inclosing said coils and coacting with said walls, a spring in said chamber, a cap for retaining said spring in place, a plunger reciprocating in said tube an impact member located between sai spring and said plunger, a handle secured to said tubular casing, circuit-controlling mechanism located within said handle and connected to the coils and a plug inclosing one end of said chamber and secured to said handle for locking said cap against rotation induced by vibration of the hammer; substantially as described.

9. 4An electric hammer comprising the combination of a tubular frame member, a plunger reciprocating therein, a solenoid coil on the frame member, a terminal block secured to the frame member, a casing .inclosing the coil, permanently attached circuit connections between the terminals on said block and said coil, a handle secured to the casing and frame member having a cavity therein, two contacts located at the base of said cavity, permanently attached circuit connections between said contacts and the terminals on said block, an insulated tube detachably mounted within said cavity, a pair of contacts mounted at the end of said tube, a movable carrier mounted withinl said tube and provided with contacts adapted to coact with the pair of contacts'.

mounted at the end of said tube, and mea-ns whereby said last-named pair of contacts may be detachably connected 4to the two contacts located at the base of the cavity to permit the removal of said insulated tube and parts associated therewith without disturbing the permanent circuit connections or removin said handle.

10. An e ectric hammer comprising the combination of a frame member havln a tubular portion with an enlarged cham er at one end, a plunger reciprocating in the tubular portion, coils encircling the tubular portion, a casing inclosing the coils, an annular nozzle threaded to one end of the frame member and slipped over the adjacent end of the casing, a tool guide attached to said nozzle and bearingagainst the end of the frame member, a spring located within the chamber, an im act member having a portion fitting within the tubular portion of the frame member and an enlarged portion fitting within the enlarged chamber, a handle havin a portion surrounding said chamber in te end of said casing distant from said nozzle, and means for connecting the handle to said casing; substantially. as described.

11. An electric hammer comprisin the combination of a frame member of tu ular form having a chamber enlarged at one end, a plunger reciprocating within said member, a spring located in the enlarged end of said chamber and coacting with the pluner, a cap attached to said frame member or holdingsaid spring in place, a solenoid collencirclmg said chamber, a tubular casingI lncloslng the coil and member and connected to the member at one end of the hammer, a handle having a tubular end adapted to fit over the casing at the opposite end of the hammer, a sleeve secured to the Casing adjacent the tubular end of the handle, a collar adapted to be connected to the tubular end of the handle and having :L lip adapted to engage said sleeve, and a closure for the end of the chamber secured to the handle and engaging the frame mem- 10 ber and cap to lock sald cap in place; substantially as described.

In testimony whereof I aix my signa.-4 ture, in presence of two witnesses.

ALEX WENDELBURG. Witnesses:

JOHN C. PENNIE, M. A. Bru.. 

